Hey folks,

It's been awhile since I posted here. Building a new house. It's done so I'd like to see if I can find an answer to a question I've been pondering for a long time.

Why in the world were so many older dozer blade lift mechanisms so complicated? Did someone have patent protection on a direct cylinder to blade connection like seen on most newer blades?

I've got RD4 with a Kay-Bruner blade with so many pins and bushings that are worn that it's hard to control. A little wear in each one makes for a lot of uncontrolled movement of the blade.

Just really curious.

Thanks, Mike

I've often wondered about that myself.....seems like they went to great extremes to build an odd ball contraption to do the job.
I guess most of it stems from the fact that these tractors were not originally designed or foreseen as dozers......plus the desire to be able to mount on both narrow and wide gage limited the options. None of them were close to getting it right until the hardnose hydraulic cylinder mounting systems came about.

And yet it's not like it wasn't done. I've got this beautiful blade mount on my little 1941 Cletrac HG that has a very direct linkage. I don't know if the mount is of a different age, and it certainly looks custom built for this tractor, but it's very simple and strong as well as made to reinforce the frame at the attachment points. They made them, like mine with a hydraulic tilt or like another one I've got, with hydraulic angle. I think they could even be combined to have both for sort of 6 way blade. (Maybe a project when I have more time than sense.) It would have been mighty heavy on the front of the tractor but still pretty cool.

Photo of the Anderson blade with tilt mechanism: http://groups.msn.com/MikesRustyandShinyStuff/constsructionequipment.msnw?action=ShowPhoto&PhotoID=372

MikeA

Interesting, that's a nice HG. I have a couple of Cletracs, an AG and an AD. I started to fabricate a blade patterned after the Anderson set up but.....another project back burnered. Got any more pics of how that internal blade tilt mechanism works? Thanks

Both based on the fact that hydraulics were very new at the time...

A) Since seal technology was in its infancy, maybe all the levers, pins and links isolated the rams from direct impact loads that could spike the pressures enough to blow out the piston or gland seals.


Like anything new and unproven, hydraulics were regarded with some skepticism by consumers, and building a system that looked more mechanical was a selling point.

CS

Hydraulic pressures used in the early days were very low, therefore the cylinders used were quite large. Direct acting cylinders would have been very bulky hanging on the front. Mechanical leverage was used since the cylinder push was less than modern hydraulics, as well.

Check out the LaPlant Choate blades used on the Cat 60 and 30 models from the 20's and 30's. The cylinder used on the back of the blade attachment was quite large.

Chuck Bos

Mike, that is a beautiful paint job on the Cletrac. I've wondered if it would not have been a lot more efficient to put the cylindar at the front of the tractor to pull more or less directly upward on the blade instead of at an angle to the blade. I'm obviously no engineer, but it would seem that it would take less energy to pull up instead of at an angle. I think some modern Cats do pretty much that now days. GWH

Thanks, gwh. That urethane does look like it's wet when new. I used ProLine paint which, here in San Diego, is what they use at the shipyards for tank lining and environments with high abrasive action on the paint. It's holding up as well as you could expect on a tractor that I actually use.

CLBos, I'm sure you're right about the angle of the cylinder, but it was probably done that way because less metal (money) was required to mount it close to the frame. As an aftermarket accessory on a farming tractor without the hard nose Old Magnet mentioned it was probably cheaper to do it that way. On most of the old blades I've seen, including the Kay Bruner on my RD4, the mechanical advantage was actually a DISadvantage, as in a little movement of the cylinder moved the blade a lot. And a little wear causes a lot of slop. The cylinders seemed to be large diameter in order to get a lot of force (probably with low hyd. pressure and the seal issues, per carlsharp). Also, on the Cletrac, the cylinders are small but more than powerful enough to lift the front of the tractor way up in the air. This also makes me suspicious that it was built after hyd. pressures went up. It won't lift the blade real high though because of that positioning... about 16-18" above the ground. Plenty high for what I do.

Old Magnet- I'll put some more photos on the website as soon as my satellite figures it wants to work: http://groups.msn.com/MikesRustyandShinyStuff/shoebox.msnw

Look on page two of the "Pictures" under the album "Construction Equipment"

Thanks for all the input! Maybe when it's all put together we've found a reason for all the Rube Goldberg madness.

Mike

Crap, the link didn't show up for the photos. Maybe if you cut and paste this one:

groups.msn.com/MikesRustyandShinyStuff/shoebox.msnw

MikeA

MikeA,
Lots of neat pictures there. Are you the owner, operator, maintainer of all that stuff:) My hats off to you if that's the case.